1. Field of the Invention
The present invention relates to a wireless sensor system for monitoring potentially dangerous or costly conditions such as, for example, smoke, temperature, water, gas and the like in a building or vehicle, and/or for monitoring energy usage or efficiency of water heaters and the like.
2. Description of the Related Art
Maintaining and protecting a building or complex is difficult and costly. Some conditions, such as fires, gas leaks, etc., are a danger to the occupants and the structure. Other malfunctions, such as water leaks in roofs, plumbing, etc., are not necessarily dangerous for the occupants, but can, nevertheless, cause considerable damage. In many cases, an adverse condition such as water leakage, fire, etc., is not detected in the early stages when the damage and/or danger is relatively small. Sensors can be used to detect such adverse conditions, but sensors present their own set of problems. For example, adding sensors, such as, for example, smoke detectors, water sensors, and the like, in an existing structure can be prohibitively expensive due to the cost of installing wiring between the remote sensors and a centralized monitoring device used to monitor the sensors. Adding wiring to provide power to the sensors further increases the cost. Moreover, with regard to fire sensors, most fire departments will not allow automatic notification of the fire department based on the data from a smoke detector alone. Most fire departments require that a specific temperature rate-of-rise be detected before an automatic fire alarm system can notify the fire department. Unfortunately, detecting fire by temperature rate-of-rise generally means that the fire is not detected until it is too late to prevent major damage.
When a relatively large number of sensor units are used, as in, for example, a commercial building, apartment building, etc., then correlating an identification code in the sensor unit with a location of the sensor unit can become difficult. Correlating the location of a sensor unit with an identification code for the sensor unit can make it difficult to install and maintain the sensor system. Moreover, errors in correlating the location of the sensor unit with an identification code of the sensor unit can lead to potentially life-threatening delays when a sensor reports a dangerous condition and the report sensor cannot be located.